JP2004015494A - Hierarchy modulation broadcast receiving system and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily extract desired hierarchy at a real time. <P>SOLUTION: The hierarchy modulation broadcast receiving system 1 for receiving a broadcast wave 2 transmitted by hierarchy modulation and outputting digital data of each multiplexed hierarchy is provided with a hierarchy setting means 6 for receiving hierarchy setting information indicating an arbitrarily selected hierarchy out of each hierarchy, and selection outputting means 4, 6 and 7 for selecting and outputting the digital data of the hierarchy indicating the hierarchy setting information. Only the digital data of the hierarchy indicating the hierarchy setting information are selectively output. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a receiving apparatus and a receiving method for hierarchical modulation broadcasting.
[0002]
[Prior art]
Generally, a digital broadcast receiver is provided with an output of a moving picture experts group 2-transport stream (MPEG2-TS) (hereinafter, referred to as a “TS output”) as an output of a signal obtained by reception. MPEG2-TS is a format for dividing video and audio data compressed by MPEG2 into predetermined fixed lengths for transmission. When receiving a modulated wave transmitted by hierarchical modulation, a conventional terrestrial digital broadcast receiver demodulates and decodes the modulated wave, and outputs digital data of all layers as MPEG2-TS. Hierarchical modulation means that when transmitting a broadcast wave, the transmission bandwidth is divided into a plurality of layers, and modulation is performed using a different modulation method for each layer. Such a hierarchical transmission scheme for performing hierarchical modulation and transmitting is used, for example, in ISDB-T (Integrated Service Digital Broadcasting-Terrestrial), which is scheduled to be adopted as a terrestrial digital broadcasting scheme in Japan.
[0003]
FIG. 8 shows a method of receiving a broadcast wave that has been subjected to hierarchical modulation and extracting data of a required layer from the obtained time-division multiplexed digital data of each layer. In the figure, reference numeral 2 denotes a modulated wave subjected to hierarchical modulation, and reference numeral 61 denotes a broadcast station or a modulator that outputs the modulated wave 2. The modulated wave 2 is divided into three layers and subjected to hierarchical modulation. Let each layer be A layer, B layer, and C layer. 62 is a terrestrial digital broadcast receiver for receiving the modulated wave 2; 63 is a storage medium or TS streamer for storing the TS output from the terrestrial digital broadcast receiver 62; A TS analyzer for extracting hierarchical data of a hierarchy desired by the user.
[0004]
In this configuration, in order to receive the modulated wave 2 from the broadcast station 61 or the like and obtain digital data of a desired hierarchy, first, a terrestrial digital broadcast receiver 62 obtains a TS output 65 based on the modulated wave 2, This is stored in the storage medium 63 or the like. At this time, the TS output 65 includes data on all the layers A to C. Next, based on the TS output stored in the storage medium 63 or the like, digital data of a desired hierarchy is extracted using the TS analyzer 64. As a result, if the desired layers are the A and B layers, a TS output 66 obtained by removing the data of the C layer from the TS output 65 can be obtained.
[0005]
[Problems to be solved by the invention]
However, according to this conventional technique, in order to obtain data of a desired hierarchy, a TS output 65 including data of all hierarchies is temporarily stored in a storage medium or the like 63, and then the TS output 65 is obtained using a TS analyzer 64. The work of extracting the data of the hierarchy must be performed. Therefore, complicated operations are required to obtain data of a desired hierarchy, and data of a desired hierarchy cannot be extracted in real time.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a receiving apparatus and a receiving method of a hierarchical modulation broadcast capable of easily extracting data of a desired hierarchy in view of the problems of the related art. Another object of the present invention is to enable data of a desired hierarchy to be extracted in real time.
[0007]
[Means for Solving the Problems]
In order to achieve this object, a hierarchically modulated broadcast receiving apparatus according to the present invention includes: a hierarchically modulated broadcast receiving apparatus that receives broadcast waves that are hierarchically modulated and transmitted and outputs data of each hierarchical level; Layer setting means for receiving layer setting information indicating the selected one, and among the data of each layer capable of receiving and outputting the broadcast wave, selecting the data of the layer indicated by the layer setting information, And a selection output means for outputting.
[0008]
Here, the broadcast of the hierarchically modulated broadcast wave corresponds to, for example, a broadcast using the ISDB-T system which is scheduled to be adopted as a terrestrial digital broadcast system in Japan. As the data of each layer, for example, a transport stream multiplexed by a packet multiplexing method according to the MPEG-2 system corresponds.
[0009]
In this configuration, when the layer setting means accepts the layer setting information and the receiving device starts receiving the hierarchically modulated broadcast wave, the receiving device obtains the demodulated wave by performing demodulation, decoding, and the like on the received modulated wave. The output of the data of each layer to be started. At the time of the output, the selecting means selectively outputs only the data of the layer matching the layer indicated by the layer setting information from the data of each layer. Therefore, by providing the layer setting information indicating the layer of the required data to the layer setting means, it is possible to easily obtain only the data of the necessary layer in real time.
[0010]
In the hierarchical modulation broadcast receiving apparatus according to a second aspect, in the first aspect, the selection output means sequentially outputs reception layer information indicating the layer for data of each layer obtained sequentially by receiving the broadcast. It is characterized by comprising receiving layer information generating means for performing the selective output based on the receiving layer information.
[0011]
In the hierarchical modulation broadcast receiving apparatus according to a third aspect, in the second aspect, the selection output means is configured such that a layer indicated by the received layer information sequentially output matches one of the layers indicated by the layer setting information. And a control signal output means for outputting a control signal which is turned on at the time, and performing the selective output based on the control signal.
[0012]
In the hierarchical modulation broadcast receiving apparatus according to a fourth aspect, in the third aspect, when the control signal is on, the selection output means receives the broadcast wave and outputs data of each layer obtained sequentially as it is, When the control signal is off, there is provided a selection means for performing the selective output by setting an associated clock level to a fixed value.
[0013]
In the hierarchical modulation broadcast receiving apparatus according to a fifth invention, in the third invention, when the control signal is on, the selection output means receives the broadcast wave and outputs data of each layer obtained sequentially as it is, When the control signal is off, a selection unit for outputting the null packet by outputting a null packet is provided.
[0014]
According to a sixth aspect of the present invention, in the hierarchical modulation broadcast receiving apparatus according to any one of the first to fifth aspects, the hierarchical setting means has an input means for inputting the hierarchical setting information.
[0015]
According to a seventh aspect of the present invention, in the hierarchically modulated broadcast receiving apparatus according to any one of the first to fifth aspects, the hierarchical setting means receives and accepts the hierarchical setting information transmitted from outside the apparatus. It is characterized by.
[0016]
An hierarchically-modulated broadcast receiving apparatus according to an eighth aspect of the present invention is the hierarchically-modulated broadcast receiving apparatus according to any of the first to seventh aspects, further comprising: a selection function on / off means for enabling and disabling a function of selective output by the selection output means. It is characterized by having.
[0017]
A hierarchical modulation broadcast receiving apparatus according to a ninth aspect is characterized in that, in any one of the first to eighth aspects, the data is in a transport stream format conforming to MPEG-2.
[0018]
A hierarchically modulated broadcast receiving method according to a tenth aspect of the present invention is a hierarchically modulated broadcast receiving method for receiving broadcast waves transmitted by hierarchical modulation and outputting data of each hierarchical layer. And a selection output step of selecting and outputting data of a layer indicated by the layer setting information from data of each layer capable of receiving and outputting the broadcast wave. And characterized in that:
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a configuration of a terrestrial digital broadcast receiver according to a first embodiment of the present invention. As shown in FIG. 1, the receiver 1 receives a modulated wave 2 that is hierarchically modulated and transmitted, and outputs time-division multiplexed digital data of each layer. The receiver 1 includes an input unit 5 including a switch or the like for inputting layer setting information indicating an arbitrarily selected one of the layers, and a collator 6 for receiving the input layer setting information. Of the digital data of each layer that can receive and output the modulated wave 2, only the digital data of the layer indicated by the layer setting information is selectively output.
[0020]
Reference numeral 4 in the figure denotes a demodulator / decoder that demodulates and decodes a modulated signal obtained by receiving the modulated wave 2 by the antenna 3, and outputs multiplexed digital data of each layer as a TS output. The demodulator / decoder 4 also sequentially outputs hierarchical information indicating the hierarchical level of digital data of each hierarchical level sequentially obtained by receiving the modulated wave 2. The collator 6 outputs a control signal that is turned on when the layer indicated by the layer information sequentially output from the demodulator 4 matches one of the layers indicated by the layer setting information described above. Reference numeral 7 in the figure denotes a TS selector for selectively outputting only digital data of the hierarchy indicated by the hierarchy setting information. When the control signal from the collator 6 is on, the TS selector 7 outputs the digital data from the demodulator / decoder 4 together with the accompanying clock as it is, but when the control signal is off, sets the accompanying clock to a fixed value (high level or low level). Fixed). Thus, when the control signal from the collator 6 is turned off, the output digital data becomes unreadable, and as a result, only the digital data of the hierarchy indicated by the hierarchy setting information is selectively output.
[0021]
The hierarchy information output by the demodulation decoder 4 indicates the hierarchy of the digital data currently output by the demodulation decoder 4. The control signal output from the collator 6 is 1 (on) when the layer indicated by the layer information from the demodulation decoder 4 matches one of the layers indicated by the set layer setting information, and matches any of them. If not, it is a 1-bit signal that is 0 (off).
[0022]
FIG. 2 shows the configuration of the collator 6. As shown in the figure, the collator 6 receives 2-bit hierarchical information (I1, I0) from the demodulator / decoder 4 and 3-bit hierarchical setting information (S2, S1, S0) from the hierarchical setting means 5. Is entered. In the layer information, “00” indicates invalid, “01” indicates layer A, “10” indicates layer B, and “11” indicates layer C. In the setting information, “000” is invalid, “001” is the C layer, “010” is the B layer, “011” is the B and C layers, “100” is the A layer, “101” is the A and C layers, and “101” is the A and C layers. “110” means the A and B layers, and “111” means the A, B and C layers (all layers). That is, the bits S2, S1, and S0 are used for setting the A layer, the B layer, and the C layer, respectively.
[0023]
The collator 6 receives NOT circuits 31 and 32 that receive the bits I0 and I1 of the hierarchy information as inputs, an AND circuit 33 that receives the bits I0 and I1 as inputs, an output of the NOT circuit 31, and the bit I1 of the hierarchy information. An AND circuit 34, an AND circuit 35 receiving the output of the NOT circuit 32 and the bit I0 of the hierarchy information, an AND circuit 36 receiving the output of the AND circuit 33 and the bit S0 of the hierarchy setting information, and the output and hierarchy of the AND circuit 34 An AND circuit 37 which receives the bit S1 of the setting information as an input, an AND circuit 38 which receives an output of the AND circuit 35 and an input of the bit S2 of the hierarchy setting information, and outputs of the AND circuits 36 to 38 as inputs and outputs a control signal. An OR circuit 39 is provided.
[0024]
In this configuration, when a modulated signal based on the modulated wave 2 is input to the demodulator / decoder 4 via the antenna 3, the demodulator / decoder 4 demodulates and decodes the modulated signal to transmit digital data of all layers obtained in the TS. In addition to outputting to the selector 7, layer information indicating the layer of the digital data of each layer to be sequentially output is output to the collator 6. Then, the collator 6 collates the layer set in advance by the layer setting means 5 with the layer information from the demodulator / decoder 7, and when the layer indicated by the layer information matches any of the set layers. The control signal to be output is turned on, and when none of them matches, the control signal is turned off. For example, assuming that the layer setting information (S2, S1, S0) is "110" (setting of layers A and B) and the layer information is "01" (layer A), the circuit shown in FIG. Is turned on. Thereafter, if the layer information (I1, I0) changes to "11" (layer C), the control signal is turned off. The TS selector 7 outputs the digital data from the demodulator 4 only when the control signal from the collator 6 is on, and makes the output zero when it is off. As a result, the receiver 1 can output only the digital data that matches the set hierarchy among all the digital data obtained by reception.
[0025]
FIG. 3 shows an output example of each unit of the receiver 1. The output to the TS selector 7 of the demodulator / decoder 4 based on the modulation signal from the antenna 3 is digital data having a hierarchical configuration in which all the hierarchies are A hierarchies, B hierarchies, and C hierarchies as shown in FIG. In this case, the hierarchical information output from the demodulator / decoder 4 in synchronization with this is as shown in FIG. This hierarchical information is transmitted to the demodulator / decoder 4 by a TMCC (Transmission and Multiplexing Configuration Control) signal for identifying a transmission multiplex configuration including transmission control information such as a modulation scheme and a coding rate, which is separated from the modulation signal. Can be obtained in a time series at the same position as the corresponding digital data of each layer. Assuming that the layers set in the collator 6 are the A and B layers, the control signal output from the collator 6 has the layer information of the A layer and the B layer as shown in FIG. Are turned on at "01" and "10", which indicate "0", and turned off at "11", which indicates the C layer. Therefore, the TS selector 7 outputs the data of FIG. 7A only when the hierarchical information is on, and outputs zero when it is off, as shown in FIG. Thereby, the receiver 1 can output only the data of the set A and B layers.
[0026]
FIG. 4 shows the configuration of a terrestrial digital broadcast receiver according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that hierarchy information can be set using a personal computer 8 instead of the hierarchy information setting means 5. That is, in the first embodiment, the receiver 1 itself has means for setting the hierarchy setting information, but in the present embodiment, the receiver 1 itself has an interface for receiving the hierarchy setting information, The user can input the layer setting information outside the receiver 1. The operations and configurations of the demodulator / decoder 4, collator 8 and TS selector 7 are the same as those in the first embodiment.
[0027]
9 is a display screen of the personal computer 8. On the display screen 9, a hierarchy selection screen by an application started to set hierarchy information in the receiver 1 is displayed. By checking a check box corresponding to each of the A to C layers with a pointing device or the like, any one or two or all of the A to C layers can be selected. The personal computer 8 sends layer setting information indicating the layer selected in this way to the receiver 1 as needed. The receiver 1 receives this and accepts it at the collator 6.
[0028]
FIG. 5 shows a TS selector of a terrestrial digital broadcast receiver according to a third embodiment of the present invention. In the TS selector 7 of FIG. 1, digital data of a layer not set in the layer setting information is set to zero, whereas in the TS selector 51 of the present embodiment, digital data of a layer not set is converted to MPEG2- Convert to a null packet in TS. The configuration of the receiver 1 other than the TS selector 51 is the same as in the above-described first and second embodiments. The TS selector 51 generates a null packet when the control signal from the collator 6 is off, and outputs the null packet. When the control signal from the collator 6 is on, the TS selector 51 And a multiplexing unit 53 for selecting the null data from the null packet from the null packet generating unit 52 when the digital data is off, time-division multiplexing these, and outputting the selected null packet. The null packet is a packet whose packet ID is 1FFF in hexadecimal, and is treated as an invalid packet.
[0029]
For example, if the demodulator / decoder 4 outputs digital data including the layers A to C as shown in FIG. 6A and the layers set in the collator 6 are the A and B layers, The control signal from 6 is as shown in FIG. Therefore, the multiplexing unit 53 outputs the digital data of the A-layer and the B-layer from the demodulation decoder 4 as it is when the control signal is on, and generates a null packet when the control signal is off, as shown in FIG. The null packet from the unit 52 is output.
[0030]
According to this, when it is difficult to receive a specific layer due to a weak reception electric field and errors frequently occur, the layer is excluded from the setting to the collator 6 in advance, so that the data of the layer can be removed. Is converted into a null packet, so that stable digital data can be obtained.
[0031]
FIG. 7 shows a configuration of a terrestrial digital broadcast receiver according to a fourth embodiment of the present invention. Elements denoted by reference numerals 2 to 7 and 51 in the drawings are the same as those denoted by the same reference numerals in FIGS. 1 and 5. Reference numeral 71 denotes a switch for enabling or disabling the functions of the TS selectors 7 and 51. When the function of the TS selectors 7 and 51 is enabled by the switch 71, as described with reference to FIGS. 3 and 6 described above, the TS selectors 7 and 51 Among the digital data, only the data of the set layer is output. When the digital data is invalid, the digital data from the demodulator / decoder 4 is output as it is for all the layers.
[0032]
【The invention's effect】
As described above, according to the present invention, the layer setting information is accepted, the data of the layer indicated by the layer setting information is selected and output, and the data of the necessary layer is extracted after accumulating the data of all the layers. Such a complicated operation can be eliminated. Accordingly, digital data of a desired hierarchy can be easily and in real time acquired.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a terrestrial digital broadcast receiver according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram showing a configuration of a collator in the receiver of FIG.
FIG. 3 is a diagram illustrating an output signal of each unit in the receiver of FIG. 1;
FIG. 4 is a block diagram illustrating a configuration of a terrestrial digital broadcast receiver according to a second embodiment of the present invention.
FIG. 5 is a block diagram showing a TS selector of a terrestrial digital broadcast receiver according to a third embodiment of the present invention.
FIG. 6 is a diagram illustrating an output signal of each unit in the receiver of FIG. 5;
FIG. 7 is a block diagram illustrating a configuration of a terrestrial digital broadcast receiver according to a fourth embodiment of the present invention.
FIG. 8 is a diagram showing a conventional method of receiving a broadcast wave subjected to hierarchical modulation and extracting data of a necessary layer from digital data of each layer obtained by time division multiplexing.
[Explanation of symbols]
1, 62: terrestrial digital broadcast receiver, 2: modulated wave, 3: antenna, 4: demodulation decoder, 5: input means, 6: collator, 7, 51: TS selector, 8: personal computer, 9: display Screens 31, 32: NOT circuit, 33-38: AND circuit, 39: OR circuit, 52: Null packet generator, 53: Multiplexer, 61: Broadcasting station or modulator, 63: Storage media, etc., 64: TS analyzer, 65, 66: TS output.

Claims (10)

In a hierarchically modulated broadcast receiving device that receives broadcast waves transmitted by hierarchical modulation and outputs data of each layer,
Layer setting means for receiving layer setting information indicating an arbitrarily selected one of the layers;
Selecting and outputting means for selecting and outputting the data of the layer indicated by the layer setting information from the data of each layer capable of receiving and outputting the broadcast wave. Receiver. The selection output means includes reception hierarchy information generation means for sequentially outputting reception hierarchy information indicating the hierarchy for data of each hierarchy sequentially obtained by receiving the broadcast wave, and performing the selection based on the reception hierarchy information. The hierarchically-modulated broadcast receiving apparatus according to claim 1, wherein the hierarchically-modulated broadcast receiving apparatus performs a dynamic output. The selection output unit has a control signal output unit that outputs a control signal that is turned on when a layer indicated by the reception layer information sequentially output matches one of the layers indicated by the layer setting information, The apparatus according to claim 2, wherein the selective output is performed based on the control signal. The selection output means, when the control signal is on, receives the broadcast wave and outputs the data of each layer obtained as it is, and when the control signal is off, sets the associated clock level to a fixed value. The hierarchically modulated broadcast receiving apparatus according to claim 3, further comprising a selection unit that performs the selective output. The selection output means, when the control signal is on, receives the broadcast wave and outputs the data of each layer obtained sequentially, as it is, and outputs the null packet when the control signal is off, thereby outputting the selective output. 4. The hierarchically modulated broadcast receiving apparatus according to claim 3, further comprising a selection unit for performing the selection. The hierarchical modulation broadcast receiving apparatus according to any one of claims 1 to 5, wherein the hierarchy setting means includes an input means for inputting the hierarchy setting information. The hierarchical modulation broadcast receiving apparatus according to any one of claims 1 to 5, wherein the hierarchical setting means receives and accepts the hierarchical setting information transmitted from outside the apparatus. The hierarchical modulation broadcast receiving apparatus according to any one of claims 1 to 7, further comprising a selection function on / off unit for enabling and disabling a function of selective output by the selection output unit. 9. The hierarchically-modulated broadcast receiving apparatus according to claim 1, wherein the data is in a transport stream format conforming to MPEG-2. In the hierarchical modulation broadcast receiving method of receiving broadcast waves transmitted by hierarchical modulation and outputting data of each hierarchy,
A layer setting step of receiving layer setting information indicating an arbitrarily selected one of the layers;
Selecting and outputting the data of the layer indicated by the layer setting information from the data of each layer capable of receiving and outputting the broadcast wave. Receiving method.

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